1. Field of the Invention
The present invention relates to a sighting system for weapons such as archery bows, cross bows and firearms, used in hunting and/or target shooting.
2. Description of Related Technology
It has long been recognized that weapons, such as archery bows, cross bows and firearms, are difficult to shoot with consistent accuracy without the aid of a sighting system. Many factors can contribute to the inaccuracy of a shot. Such factors include, without limitation, the distance to the target, the size of the target, the speed of the projectile, the weight of the projectile, the wind and visibility conditions, as well as how the shooter holds the weapon itself. Since the distance to the target and the projectile speed both effect the amount of drop the projectile will experience, some consider the attitude, or vertical orientation, of the weapon to be the most significant factor influencing accuracy.
In comparison to other projectiles, an arrow projected from a bow exhibits a relatively low speed, approximately 175 to 350 feet per second. While compound bows and overdraw systems have increased the speed of the arrow, and therefore lessened the amount of vertical drop, the effect of gravity still must be taken into account regardless of the length of the shot. This is typically done by changing the attitude of the bow and “holding above” the target when aiming.
While instinct shooters rely on experience and familiarity with their equipment to compensate for accuracy influencing factors, most archers prefer to use a bow sight. The typical bow sight is mounted to the riser of the bow so as to locate one or more sight pins forward of the riser, with the ends of the pins located on the same side of the riser as the arrow rest. Thus, the sight pins are generally positioned above the rest. The sight pins are vertically spaced from one another and are individually set by the archer, through trial and error, so that each pin corresponds with a predetermined shooting distance to the target. For example, one sight pin may be set for a fifteen-yard shot, a second for a twenty-five yard shot, and a third pin for a thirty-five yard shot. When set in this manner, the sight pin corresponding with the distance to the target is then aligned with the target during the actual shot.
One drawback of the above-mentioned type of sight is that the pins only provide a single sighting point for the aiming of the bow. Such a system requires that the bow be consistently held in the same position, relative to the archer, for the sight to be accurate. If the bow is held slightly higher, lower, leftward or rightward relative to the archer, then inaccuracy will be introduced into the sighting process.
As a result, a variety of secondary sights have been developed. Secondary sights, as the term is used herein, provide the archer with a secondary aiming reference. This secondary aiming reference is used in conjunction with the previously mentioned front sight and, therefore, facilitates the bow being more consistently held in the same position relative to the shooter.
In archery, perhaps the most common secondary sight is a peep sight mounted to the bow string. During use, once the bow string is brought to full draw, the archer looks through the peep sight and then aligns the appropriate sight pin on the target. By forcing the archer to look through the peep sight, the bow is held at a more consistent position relative to the archer. While a peep sight system may be considered better than a mere front sight, these systems also have their disadvantages and drawbacks. One significant drawback is that the small aperture of the peep sight significantly limits the amount of light available for viewing the sight pin and the target. This diminished visibility is compounded by the fact that the best hunting times often occur during the marginal light conditions of dawn and dusk.
Another type of secondary sight is a rear sight that is intended to be used in combination with the front sight. One such rear sight is disclosed in the present inventor's own U.S. Pat. Nos. 5,671,724 and 7,461,460, which are herein incorporated by reference. These patents discloses a rear sight ring that is located rearward of the riser, between the riser and the bow string itself, and used in combination with a front sight. In aligning a bow equipped with such a sight, the sighting elements of the rear sight are always centered on the same pin of the front sight, for example the twenty-five yard pin. This properly orients the bow. While maintaining this alignment between the rear sighting elements and the designated front pin, the appropriate distance pin is then located on the target.
Torque or horizontal orientation is also a significant, but often overlooked, factor influencing accuracy in shooting a weapon. If the weapon is not consistently held in the same horizontal orientation, the projectile will be directed left or right of the target. With an archery bow for example, the riser and bow string are independent elements from one another. It is therefore possible to hold the riser and the bow string differently, relative to one another, during subsequent shots. Specifically, when the riser is held in the archer's hand, if the riser is rotated about a vertical axis extending through the archer's hand (i.e. upward through the grip of the riser), then a sight located in the front of the riser will move in one direction, while a fixed point to the rear of the riser will rotate in the opposite direction. Thus, at full draw, the bow string can be held in a consistent position relative to the archer, but the riser may be rotated via the archer's hand about a vertical axis. When held in this manner, it is still possible to align the front sight in the presence of this torque, but the arrow will be projected off-line from the target, toward the left or the right, depending on which directed the riser is rotated.
Even with the advent of the sights described in the above mentioned patents, there still remains a degree of view obstruction, by the rear sight, of the target. As with the peep sight, this obstruction is compounded by the locating of the rear sight closer to the eye of the shooter.
In view of the above limitations and drawbacks, it is seen that there exists a need for an improved sight that can be used to more accurately aim a weapon at the target, without overly complicating the shooting process, and without compromising the vision of the shooter during lowlight situations.